Di-tert-butylphenol compounds useful as anti-inflammatory agents

ABSTRACT

The subject invention relates to compounds having the structure: ##STR1## wherein (a) X is selected from hydroxy, C 1  to about C 2  alkanoxy, thiol, C 1  to about C 2  alkanylthiol, and halo; 
     (b) R and R&#39; are each independently selected from C 1  to about C 3  straight or branched alkanyl, and C 3  to about C 4  cyclic alkanyl; or R and R&#39; are bonded together to form a C 3  to about C 6  cyclic alkanyl ring, or a C 3  to about C 5  cyclic heteroalkanyl ring having one oxygen or sulfur atom in the ring, the heteroatom not being bonded to the carbon to which X is bonded; and R and R&#39;, or the ring formed by them when bonded together, are each, independently, unsubstituted or monosubstituted with a substituent selected from halo, hydroxy, thiol, C 1  to about C 2  alkanoxy, and C 1  to about C 2  alkanylthiol. 
     The subject invention also relates to the pharmaceutical compositions comprising the above compounds, and methods of treating inflammation using the compounds.

TECHNICAL FIELD

The subject invention relates to nonsteroidal anti-inflammatory drugs, particularly to substituted di-tert-butylphenol compounds.

BACKGROUND OF THE INVENTION

Di-tert-butylphenol compounds are a class of compounds known for their use as stabilizers for plastics, oils and fats; see, e.g., U.S. Pat. No. 3,711,544 issued to Engelhardt, Fruhstorfer, Hesse, Dennler & Baumer on Jan. 16, 1973.

Certain di-tert-butylphenol compounds and other compounds structurally related thereto have been found to have significant anti-inflammatory and/or analgesic activity. Such compounds, processes for making them, and uses for them are disclosed in the following references: U.S. Pat. Nos. 3,784,701 issued to Tomcufcik, Grassing & Sloboda on Jan. 8, 1974; 3,917,672 issued to Schmidt on Nov. 4, 1975; 4,124,725 issued to Moore on Nov. 7, 1978; 4,130,666 issued to Moore on Dec. 19, 1978; 4,165,383 issued to Moore on Aug. 21, 1979; 4,172,082 issued to Moore on Oct. 23, 1979; 4,357,345 issued to Moore on Nov. 2, 1982; 4,418,074 issued to Moore on Nov. 29, 1983; 4,440,784 issued to Katsumi, Kondo, Yamashita, Hidaka, Hosoe, Ariki, Yamashita & Watanobe on Apr. 3, 1984; 4,535,165 issued to Moore on Aug. 13, 1985; 4,677,113 issued to Bell & Moore on Jun. 30, 1987; 4,708,966 issued to Loomans, Matthews & Miller on Nov. 24, 1987; 4,714,776 issued to Bell & Moore on Dec. 22, 1987; 4,833,155 issued to Muchowski, Greenhouse, Young & Murthy on May 23, 1989; 4,968,710 issued to Rustad on Nov. 6, 1990; 4,982,006 issued to Hudec on Jan. 1, 1991; 5,086,064 issued to Capris, Conner & Sircar on Feb. 4, 1992; 5,102,897 issued to Boschelli, Conner, Kostlan, Kramer, Mullican & Sircar on Apr. 7 1992; European Patent Application No. 0,212,848 of Riker Laboratories, published Mar. 4, 1987; PCT Patent Application Nos. WO 83/01774 and WO 83/91775 of Riker Laboratories, both published May 26, 1983; WO 93/07865 of The Procter & Gamble Company, published Apr. 29, 1993; Kaffenberger, R. M., T. H. Eichhold & M. J. Doyle, "Determination of Tebufelone (A New Anti-inflammatory Drug) Strength and Stability in Bulk Drug, Dosage Formulations and Feed Admixtures by Reversed-Phase High-Performance Liquid Chromatography", Journal of Chromatofiraphy, Vol. 505 (1990), pp. 349-356. Such compounds are also disclosed and reviewed in Bart, D. G., "5-Lipoxygenase Inhibitors and Their Anti-inflammatory Activities", Progress in Medicinal Chemistry, Vol. 29 (1992), pp. 1-15, 45-50, and references disclosed therein.

Although a number of di-tert-butylphenol compounds have been demonstrated to exhibit anti-inflammatory activity, many such compounds exhibit little or no anti-inflammatory activity. Thus it is generally not possible to predict whether such compounds have substantial anti-inflammatory activity without testing for the activity.

It is an object of the subject invention to provide compounds which have effective anti-inflammatory, analgesic and/or anti-oxidant activity.

It is a further object of the subject invention to provide such compounds which cause few adverse side effects.

It is also an object of the subject invention to provide methods for treating inflammation and/or pain using the subject compounds.

SUMMARY OF THE INVENTION

The subject invention involves compounds having the structure: ##STR2## wherein a) X is selected from hydroxy, C₁ to about C₂ alkanoxy, thiol, C₁ to about C₂ alkanyl thiol, and halo;

b) R and R' are each independently selected from C₁ to about C₃ straight or branched alkanyl, and C₃ to about C₄ cyclic alkanyl; or R and R' are bonded together to form a C₃ to about C₆ cyclic alkanyl ring, or a C₃ to about C₅ cyclic heteroalkanyl ring having one oxygen or sulfur atom in the ring, the heteroatom not being bonded to the carbon to which X is bonded; and R and R', or the ring formed by them when bonded together, are each, independently, unsubstituted or monosubstituted with a substituent selected from halo, hydroxy, thiol, C₁ to about C₂ alkanoxy, and C₁ to about C₂ alkanylthiol.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, "alkanyl" means a saturated hydrocarbon substituent, straight, branched or cyclic chain, unsubstituted or substituted. Unless otherwise specified, preferred alkanyl is unsubstituted; preferred is methyl or ethyl.

As used herein, "alkanoxy" means a substituent having the structure Q--O--, where Q is alkanyl.

As used herein, "alkanylthiol" means a substituent having the structure Q--S--, where Q is alkanyl.

As used herein, "halo" means fluoro, chloro, bromo or iodo. The subject invention involves particular di-tert-butylphenol compounds having the following structure: ##STR3##

In the above structure, X is selected from hydroxy, C₁ to about C₂ alkanoxy, thiol, C₁ to about C₂ alkanylthiol, and halo. Preferred X is hydroxy. Preferred X is also halo; more preferred X is fluoro, and especially chloro. Also preferred X is methoxy or methylthiol.

In the above structure, R and R' are each, independently, selected from C₁ to about C₃ straight or branched alkanyl, and C₃ to about C₄ cyclic alkanyl; or R and R' are bonded together to form a C₃ to about C₆ cyclic alkanyl ring, or a C₃ to about C₅ cyclic heteroalkanyl ring having one heteroatom selected from oxygen and sulfur, the heteroatom not being bonded to the carbon to which X is bonded.

R is preferably methyl, ethyl, n-propyl or i-propyl; more preferably methyl or ethyl; most preferably methyl. R is also preferably cyclopropyl.

R' is preferably methyl or ethyl, most preferably methyl.

When R and R' are bonded together to form a cyclic ring, the ring is preferably cyclopropyl, cyclobutyl or cyclopentyl. When a heteroatom is included in the ring, the heteroatom is oxygen or sulfur, preferably sulfur. Such heterocyclic ring preferably has three or four carbon atoms plus the heteroatom in the ring.

R and R', or the ring formed by them when bonded together, are each, independently, unsubstituted or monosubstituted with a substituent selected from halo, hydroxy, thiol, C₁ to about C₂ alkanoxy and C₁ to about C₂ alkanylthiol. Preferably R and R', or the ring formed by them, are unsubstituted. If substituted, preferred substituents are halo, especially chloro. Another preferred substituent is methoxy.

Preferred compounds of the subject invention include those having the above structure with X, R and R' as indicated in the following table:

    ______________________________________                                         Compound No.   X        R           R'                                         ______________________________________                                         1              Cl       Me          Me                                         2              Cl       Et          Et                                         3              F        Me          Me                                         4              OH       Me          Me                                         5              OH       cyclo-Pr    Me                                         6              OH       CH.sub.2 Cl Me                                         7              OH       (CH.sub.2).sub.3 Cl                                                                        Me                                         8              OH       CH.sub.2 --CH.sub.2 --CH.sub.2                         9              OH       CH.sub.2 --CH.sub.2 --CH.sub.2 --CH.sub.2              10             OH       CH.sub.2 --CH.sub.2                                    11             OH       CH.sub.2 --CH.sub.2 --S--CH.sub.2                      12             SH       Me          Me                                         13             OH       CH.sub.2 --OMe                                                                             Me                                         14             Cl       CH.sub.2 CH.sub.2 CH.sub.2                             ______________________________________                                    

In order to determine and assess pharmacological activity, testing of the subject compounds in animals is carried out using various assays known to those skilled in the art. The anti-inflammatory activity of the subject compounds can be conveniently demonstrated using an assay designed to test the ability of the subject compounds to antagonize the local edema which is characteristic of the inflammatory response. Examples of such known tests include the rat carrageenan edema test, the oxazolone-induced inflamed mouse ear test, and the mouse arachadonic acid-induced inflamed ear test. Analgesic activity may be tested in art-known models such as the phenylbenzoquinone-induced writhing test in mice, and the Randall & Selitto test in rats. Another useful art-known test is the rat adjuvant arthritis test which is a useful model for assessing anti-inflammatory activity, anti-arthritic and anti-resorptive activity in a chronic, rather than an acute, model.

These and other appropriate tests for pharmacological activity are disclosed and/or referred to in U.S. Pat. No. 4,130,666 issued to Moore on Dec. 19, 1978; U.S. Pat. No. 4,431,656 issued Feb. 14, 1984 to Katsumi, et al.; U.S. Pat. No. 4,440,784 issued to Katsumi, et al. on Apr. 3, 1984; Japanese Patent Application 85154315 of Katsumi, et al., published Mar. 28, 1985; European Patent Application No. 0,059,090 of Yamanuchi Pharmaceutical Company Ltd., published Sep. 1, 1982; Opas, E. V., R. J. Bonney & J. L. Humes, "Prostaglandin and Leukotriene Synthesis in Mouse Ears Inflamed by Arachadonic Acid", The Journal of Investigative Dermatology, Vol. 84, No. 4 (1985), pp. 253-256; Swingle, K. F., R. L. Bell & G. G. I. Moore, "Anti-inflammatory Activity of Antioxidants", Anti-inflammatory and Antirheumatic Drugs, Vol. III, Chapter 4, K. D. Rainsford, ed., CRC Press, Inc., (1985), pp. 105-126; Adamkiewicz, V. W., W. B. Rice & J. D. McColl, "Antiphlogistic Effect of Trypsin in Normal and in Adrenalectomized Rats", Canadian Journal of Biochemistry& Physiology, Vol. 33 (1955), pp. 332-339; Sellye, H., "Further Studies Concerning the Participation of the Adrenal Cortex in the Pathogenesis of Arthritis", British Medical Journal, Vol. 2 (1949), pp. 1129-1135; and Winter, C. A., E. A. Risley & G. W. Nuss, "Carrageenan-Induced Edema in Hind Paw of the Rats as an Assay for Antiinflammatory Drugs" Proceedings of Society of Experimental Biology and Medicine, Vol. 111 (1962), pp. 544-547; Otterness, I., & M. L. Bliven, "Laboratory Methods for Testing Nonsteroidal Antiinflammatory Drugs", Nonsteroidal Antiflammatory Drugs. Chapter 3, J. G. Lombardino, ed., John Wiley & Sons, Inc. (1985), pp. 111-252. Hitchens, J. T., S. Goldstein, L. Shemano & J. M. Beiler, "Analgesic Effects of Irritants in Three Models of Experimentally-Induced Pain", Arch. Int. Pharmacodyn., Vol. 169, No. 2 (1967) pp. 384-393; Milne, G. M. & T. M. Twomey, "The Analgetic Properties of Piroxicam in Animals and Correlation with Experimentally Determined Plasma Levels", Agents and Actions, Vol. 10, No. 1/2 (1980), pp. 31-37; Randall, L. O. & J. J. Selitto, "A Method for Measurement of Analgesic Activity on Inflamed Tissue", Arch. Int. Pharmacodyn., Vol. 111, No. 4 (1957), pp. 409-419; Winter, C. A. & L. Faltaker, "Nociceptive Thresholds as Affected by Parenteral Administration of Irritants and of Various Antinociceptive Drugs", J. Pharmacol. Exp. Ther., Vol. 148, No. 3 (1965), pp. 373-379; the disclosure of all these references are incorporated herein by reference.

Many anti-inflammatory drugs, particularly non-steroidal anti-inflammatory drugs (NSAIDs) cause undesirable gastrointestinal side effects, especially when dosed perorally; such side effects may include ulcers and erosions. These side effects, which are often asymptomatic, can become serious enough to require hospitalization and can even be lethal. Compounds of the subject invention generally cause fewer such gastrointestinal side effects compared to other NSAIDs, even compared to many other di-tert-butylphenol derivatives. Some compounds of the subject invention are even gastroprotective, protecting the stomach from ulcers and erosions, particularly those caused by ethanol or other NSAIDs.

Certain NSAIDs, including certain di-tert-butylphenol derivatives, when dosed systemically, cause an undesirable increase in systemic levels of certain liver enzymes. Compounds of the subject invention generally cause less of such liver enzyme side effects compared to other di-tert-butylphenol compounds.

Compounds useful in the subject invention can be made using the following general reaction schemes: ##STR4## For the above scheme, Tf is trifluoromethanesulfonate; TBAF is tetrabutylammonium fluoride, and DAST is diethylaminosulfur trifluoride.

The following non-limiting examples provide further information regarding synthesis of the subject compounds.

EXAMPLE 1 1-(3,5-Di-tert-butyl-4-hydroxyphenyl)-3-hydroxy-3-methyl-butan-1-one

A stirred solution of 3,5-di-tert-butyl-4-hydroxyacetophenone (Apim Chemicals, Ltd.) (4 g) in dry methylene chloride (250 mL) is cooled to -78° C. and di-isopropyl ethylamine (7.3 mL) is added followed by trimethylsilyl trifluoromethanesulphonate (Aldrich Chemical Co.) (8.0 mL). The mixture is stirred at -78° C. for 10 minutes and is allowed to warm to ambient temperature over 1 hour. The mixture is cooled again to -78° C. and dry acetone (4.05 mL) is added dropwise. After stirring for 25 minutes, the mixture is washed with 1N aqueous hydrochloric acid and brine. The organic solution is dried over anhydrous sodium sulfate and the solvent is removed under reduced pressure. The crude product is dissolved in methanol-1N aqueous HCl mixture (10:1, v/v, 200 mL) and the homogenous solution is stirred for 1 hour at room temperature. Methanol is removed under reduced pressure; the mixture is washed with methylene chloride. The organic extracts are washed: with aqueous sodium bicarbonate, brine, dried over anhydrous sodium sulfate, and the solvent is removed under reduced pressure. The crude product is crystallized from hexane to give 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-hydroxy-3-methyl-butan-1-one as orange crystals. Two additional crystallizations give product of analytical purity, mp 113°-14° C.

EXAMPLE 2 1-(3,5-Di-tert-butyl-4-hydroxyphenyl)-3-chloro-3-methyl-butan-1-one

In a 1 L round bottom flask, equipped with internal thermometer, magnetic stirrer and septum inlet, is placed a solution of 3,3-dimethylacryloylchloride (Aldrich Chemical Co.) (18.4 mL, 0.166 mol) in CH₂ Cl₂) 150 mL). The stirred solution is cooled in a salt-ice bath, while TiCl₄ (18.2 mL, 0.20 mol, 1.2 eq) is added dropwise via canula at a rate such that the reaction mixture does not warm above 0° C. The solution is stirred for 10 minutes after addition is complete, and then a solution of 2,6-di-tert-butylphenol (Aldrich Chemical Co.) (34.0 g, 0.166 mol, 1.0 eq) in CH₂ Cl₂ (100 mL) is added dropwise via addition funnel. Again, the rate of addition is adjusted to maintain the reaction temperature below 0° C. The cold bath is removed, and the mixture is allowed to stir at ambient temperature for 3 hours. TLC analysis (EtOAc:hexane, 1:9) indicates the reaction to be complete. H₂ O (100 mL) is added, and the organic phase is separated, washed with additional H₂ O (2×100 mL), dried over MgSO₄, filtered, and evaporated to a dark oil (49.0 g). At this stage, the reaction mixture consists of a mixture of the desired p-chloroketone and the intermediate α,β-unsaturated ketone. The oil is taken up in 1M HCl-saturated Et₂ O (150 mL), and stirred at ambient temperature overnight. The reaction is then extracted with H₂ O (3×100 mL), dried over MgSO₄, filtered, and evaporated to a viscous dark oil. The crude product is crystallized from pentane to give 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-chloro-3-methyl-butan-1-one as a white solid, mp 101°-2° C.

EXAMPLE 3 1-(3,5-Di-tert-butyl-4-hydroxyphenyl)-3-chloro-3-ethyl-pentan-1-one

1-(3,5-Di-tert-butyl-4-hydroxyphenyl)-3-hydroxy-3-ethyl-pentan-1-one (prepared by method analogous to that of Example 1) (1.6 g) is dissolved in dry 1N hydrogen chloride solution in ethyl ether (50 mL) and the mixture is stirred at ambient temperature for 10 hours. The solution is washed three times with water, dried over anhydrous sodium sulfate and the solvent is removed under reduced pressure. The crude product is crystallized twice from petroleum ether to give 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-chloro-3-ethyl-pentan-1-one as white solid, mp 72° C.

EXAMPLE 4 1-(3,5-Di-tert-butyl-4-hydroxyphenyl)-3-fluoro-3-methyl-butan-1-one

To a stirred solution of 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-hydroxy-3-methyl-butan-1-one (2.5 g) in dry methylene chloride (30 mL) cooled to -78° C. is added diethylaminosulfur trifluoride (Aldrich Chemical Co.) (1.2 mL) and the stirring is continued for an additional 45 minutes. The mixture is washed with water and saturated aqueous sodium bicarbonate, dried over anhydrous sodium sulfate, and the solvent is removed under reduced pressure. The crude product is purified by silica gel column chromatography (hexane:ethyl acetate, 9:1) followed by crystallization from petroleum ether to give 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-fluoro-3-methyl-butan-1-one as a white solid, mp 94° C.

EXAMPLE 5 1-(3,5-Di-tert-butyl-4-hydroxyphenyl)-3-sulfhydryl-3-methyl-butan-1-one

A solution of 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-methyl-but-2-en-1-one (prepared by method analogous to that of Example 2) (2.0 g), piperidine (176 mg), and 4-methoxybenzylthiol (0.96 mL) in benzene (50 mL) is allowed to stir at 24° C. for 16 hours. Additional 4-methoxybenzylthiol (0.48 mL) is added, and the reaction mixture is stirred at 45° C. for 72 hours. The solvent is evaporated to a yellow oil, which is purified by silica gel column chromatography (hexane:ethyl acetate, 95:5) to give 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-(4-methoxyphenylmethylthio)-3-methyl-butan-1-one as a colorless oil.

To a stirred, ice-cold solution of 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-(4-methoxyphenylmethylthio)-3-methyl-butan-1-one (70 mg) in CHCl₃ (1 mL), under argon, is added CF₃ COOH (0.02 mL) via syringe. The reaction mixture is kept at 0° C. for 3 hours, and then solvent is evaporated under reduced pressure to give a brown oil. The crude material is purified twice by preparative silica gel thin layer chromatography (hexane:ethyl acetate, 9:1), to give 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-sulfhydryl-3-methyl-butan-1-one as a colorless oil.

EXAMPLE 6 1-(3, 5-Di-tert-butyl4-hydroxyphenyl)-3-methoxy-3-methyl-butan-1-one

To a stirred solution of dimethyldiphenylsilane (Lancaster Co.) (0.65 mL) in dry methylene chloride (1.5 mL) cooled to -78° C. is added trifluoromethanesulfonic acid (0.5 mL). The mixture is allowed to warm to room temperature over 1 hour. The mixture is cooled again to -78° C. and di-isopropylethylamine (0.6 mL) is added followed by a solution of 3,5-di-tert-butyl-4-hydroxyacetophenone (0.5 g) in methylene chloride (1.5 mL). The reaction mixture is stirred at -78° C. for 10 hours, diluted with methylene chloride and sequentially washed with water and brine. The organic solution is dried over anhydrous sodium sulfate, and the solvent is removed under reduced pressure. The crude product is purified by silica gel chromatography to give 1-(3,5-di-tert-butyl-4-hydroxyphenyl)-3-methoxy-3-methyl-butan-1-one as a white solid.

Using the procedure described in Example 1, the appropriate ketones can be reacted with 3,5-di-tert-butyl-4-hydroxyacetophenone to give the corresponding β-hydroxy compounds (X=OH). Using the procedure described in Example 3, the β-hydroxy compounds can be converted to the β-halo compounds (X=halo).

Compositions of the subject invention comprise a safe and effective amount of the subject compounds, and a pharmaceutically-acceptable carrier. As used herein, "safe and effective amount" means an amount of a compound sufficient to significantly induce a positive modification in the condition to be treated, but low enough to avoid serious side effects (at a reasonable benefit/risk ratio), within the scope of sound medical judgment. A safe and effective amount of a compound will vary with the particular condition being treated, the age and physical condition of the patient being treated, the severity of the condition, the duration of the treatment, the nature of concurrent therapy, the particular pharmaceutically-acceptable carrier utilized, and like factors within the knowledge and expertise of the attending physician.

Compositions of the subject invention preferably comprise from about 0.1% to about 99.9% by weight of a compound, more preferably from about 20% to about 80%, and most preferably from about 40% to about 70%.

In addition to the compound, the compositions of the subject invention contain a pharmaceutically-acceptable carrier. The term "pharmaceutically-acceptable carrier", as used herein, means one or more compatible solid or liquid filler diluents or encapsulating substances which are suitable for administration to a human or lower animal. The term "compatible", as used herein, means that the components of the composition are capable of being commingled with the subject compound, and with each other, in a manner such that there is no interaction which would substantially reduce the pharmaceutical efficacy of the composition under ordinary use situations. Pharmaceutically-acceptable carriers must, of course, be of sufficiently high purity and sufficiently low toxicity to render them suitable for administration to the human or lower animal being treated.

Some examples of substances which can serve as pharmaceutically-acceptable carriers or components thereof are sugars, such as lactose, glucose and sucrose; starches, such as cornstarch and potato starch; cellulose and its derivatives, such as sodium carboxymethyl cellulose, ethyl cellulose, cellulose acetate; powdered tragacanth; malt; gelatin; talc; solid lubricants, such as stearic acid, magnesium stearate; calcium sulfate; vegetable oils, such as peanut oil, cottonseed oil, sesame oil, olive oil, corn oil and oil of theobroma; polyols such as propylene glycol, glycerin, sorbitol, mannitol, and polyethylene glycol; alginic acid; emulsifiers, such as the Tweens®; wetting agents such as sodium lauryl sulfate; coloring agents; flavoring agents, excipients; tableting agents; stabilizers; antioxidants; preservatives; pyrogen-free water; isotonic saline; and phosphate buffer solutions.

The choice of a pharmaceutically-acceptable carrier to be used in conjunction with a subject compound is basically determined by the way the compound is to be administered.

If the subject compound is to be injected, it is preferably injected non-intravenously; the preferred pharmaceutically-acceptable carrier is sterile, physiological saline, with blood compatible suspending agent, the pH of which has been adjusted to about 7.4. Such injectable compositions preferably comprise from about 1% to about 50% of the subject compound, more preferably from about 5% to about 25%, also preferably from about 10 mg to about 600 mg of the subject compound per dose.

Suitable pharmaceutically-acceptable carriers for topical application include those suited for use in lotions, creams, gels and the like. Topical compositions preferably contain from about 1% to about 50% of an emollient, more preferably from about 5% to about 25% of an emollient. Such topical compositions preferably comprise from about 0.1% to about 50%, of the subject compound, more preferably from about 0.5% to about 10%, also preferably from about 5 mg to about 3500 mg per dose.

The preferred mode of administering the subject compound is perorally. The preferred unit dosage form is therefore tablets, capsules and the like, comprising a safe and effective amount of the compound, which is preferably from about 5 mg to about 3500 mg, more preferably from about 10 mg to about 1000 mg, and most preferably from about 25 mg to about 600 mg. The pharmaceutically-acceptable carriers suitable for the preparation of unit dosage forms for oral administration are well-known in the art. Their selection will depend on secondary considerations like taste, cost, and shelf stability, which are not critical for the purposes of the subject invention, and can be made without difficulty by a person skilled in the art.

Many of the subject compounds are hydrophobic. If it is desired to provide an aqueous-based composition or a composition soluble in or miscible with aqueous media, a solubilizing agent may be included in the composition. Non-limiting examples of such solubilizing agents include polyethylene glycol, propylene glycol, ethanol, and polyoxyethylene (35) castor oil.

Particularly preferred oral composition carriers suitable for compositions of the subject invention are disclosed in U.S. Pat. Nos. 5,189,066 of Kelm & Bruns, issued Feb. 23, 1993, entitled "Pharmaceutical Compositions of Tebufelone", and 5,281,420 of Kelm & Dobrozsi, issued Jan. 25, 1994, entitled "Solid Dispersion Compositions of Tebufelone", hereby incorporated herein by reference.

Another aspect of the subject invention is methods for treating or preventing diseases characterized by inflammation by administering a safe and effective amount of a subject compound to a human or lower animal in need of such treatment. The term "diseases characterized by inflammation", as used herein, means conditions which are known to involve inflammation, and may include conditions such as arthritis (e.g., rheumatoid arthritis, osteoarthritis, psoriatic arthritis, juvenile arthritis, Reiter's syndrome, infectious arthritis, and ankylosing spondylitis, systemic lupus, erythematosus and gout), as well as the presence of inflammation whether or not it is associated with an identifiable disease. Diseases characterized by inflammation further may include inflammation in the oral cavity (e.g., inflammation associated with gingivitis or periodontal disease); inflammation in the gastrointestinal tract, (e.g., inflammation associated with ulcers and irritable bowel disease); inflammation associated with dermatological diseases (e.g., psoriasis, acne, and other skin inflammation); inflammation associated with the respiratory tract (e.g., asthma, bronchitis, and allergies); and inflammation in the central nervous system (e.g., Alzheimer's disease).

Another aspect of the subject invention is methods for treating or preventing pain by administering a safe and effective amount of a subject compound to a human or lower animal in need of such treatment. Pain which can be treated or prevented by administering the subject compounds may include peripheral pain, menstrual pain, dental pain, and lower back pain.

Another aspect of the subject invention is methods for protecting against free radical damage resulting from oxidative stress and ischemic conditions by administering a safe and effective amount of a subject compound to a human or lower animal in need of such treatment. Such treatment may include protecting against ischemic head disease, atherosclerosis, stroke, and ischemic cell damage of heart.

Another aspect of the subject invention is methods for treating or preventing gastric or duodenal ulcers or erosions by administering a safe and effective amount of a subject compound to a human or lower animal in need of such treatment. In particular, such ulcers or erosions caused by ethanol or nonsteroidal antiinflammatory drugs (NSAIDs) can be treated and/or prevented by administration of preferred subject compounds.

Appropriate tests for determining the gastrointestinal safety or gastroprotective or gastric healing properties of the subject compounds are known.

Methods for determining acute gastrointestinal safety are disclosed and/or referred to in the following references: Unangst, P. C., G. P. Shrum, D. T. Connor, R. D. Dyer, and D. J. Schrier, "Novel 1,2,4-Oxadiazoles and 1,2,4-Thiadiazoles as Dual 5-Lipoxygenase and Cyclooxygenase Inhibitors", J. Med. Chem., Vol. 35 (1992), pp. 3691-3698; and Segawa,Y,O. Ohya, T. Abe, T. Omata, et al., "Anti-inflammatory, Analgesic, and Antipyretic Effects and Gastrointestinal Toxicity of the New Anti-inflammatory Drug N-{3-[3-(piperidinylmethyl)phenoxy]propyl}carbamoylmethylthio]ethyl 1 -(p-chlorobenzoyl) 5-Methoxy-2methyl-3-indolylacetate", Arzneim-Forsch./Drug Res., Vol. 42 (1992), pp. 954-992. In the methods disclosed therein, stomachs of the animals are typically examined two hours after dosing a compound.

Methods for determining subchronic gastrointestinal safety are disclosed and/or referred to in the following references: Melarange, R., C. Gentry, et al., "Anti-inflammatory and Gastrointestinal Effects of Nabumetone or Its Active Metabolite, 6-Methoxy-2-naphthylacetic Acid (6MNA)", Dig. Dis. Sci., Vol. 37 (1992), pp. 1847-1852; and Wong, S., S. J. Lee, et al., "Antiarthritic Profile of BF-389--A Novel Anti-inflammatory Agent With Low Ulcerogenic Liability", Agents Actions, Vol. 37 (1992), pp. 90-91.

Methods for determining acute gastroprotection are disclosed and/or referred to in the following reference: Playford, R. J., D. A. Versey, S. Haldane, M. R. Alison, and J. Calan, "Dose-dependent Effects of Fentanyl on Indometharin-induced Gastric Damage", Digestion, Vol. 49 (1991 ), pp. 198-203. In the method disclosed therein, female Lewis rats (130-175 g) are dosed perorally with the subject compound (40 mg/kg b.i.d.) or vehicle at 2 hours and immediately before administration of a gastric damaging dose of indomethacin. The rats are sacrificed 4 hours later by CO₂ asphyxiation. Gastric corpus damage (millimeters of hemorrhagic lesions) is measured by digitized imaging.

The preferred mode of administration of the subject compounds is peroral, but other known methods of administration are contemplated as well, e.g., dermatomucosally (for example, dermally, rectally and the like), and parenterally (for example, by subcutaneous injection, intramuscular injection, intraarticular injection, intravenous injection and the like). Ocular administration and inhalation are also included. Thus specific modes of administration include, without limitation, peroral, transdermal, mucosal, sublingual, intranasal, intramuscular, intravenous, intraperitoneal, subcutaneous, and topical administration.

Preferred doses of the subject compounds range from about 0.2 mg/kg to about 70 mg/kg, more preferably from about 0.5 mg/kg to about 12 mg/kg. Preferred injectable doses comprise from about 0.1 mg/kg to about 10 mg/kg of the subject compound. Preferred topical doses comprise from about 1 mg/cm² to about 200 mg/cm² of the subject compound applied to the skin surface. Preferred peroral doses comprise from about 0.5 mg/kg to about 50 mg/kg, more preferably from about 1 mg/kg to about 10 mg/kg, of the subject compound. Such doses are preferably administered from about once to about six times daily, more preferably from about twice to about four times daily. Such daily doses are preferably administered for at least one week, also preferably for at least two weeks, also preferably at least one month, also preferably for at least 2 months, also preferably for at least 6 months, 1 year, 2 years, or more.

The following non-limiting examples illustrate the subject invention.

EXAMPLE A

Pharmaceutical compositions in the form of tablets are prepared by conventional methods, such as mixing and direct compaction, formulated as follows:

    ______________________________________                                         Ingredient       Quantity (mg per tablet)                                      ______________________________________                                         Compound 1       200                                                           Microcrystalline Cellulose                                                                      100                                                           Sodium Starch Glycollate                                                                         30                                                           Magnesium Stearate                                                                               3                                                            ______________________________________                                    

When administered orally two times daily, the above composition significantly reduces the inflammation in a patient suffering from rheumatoid arthritis. A significant benefit is also achieved by twice daily administration of this composition to a patient suffering from osteoarthritis.

EXAMPLE B

A pharmaceutical composition in capsule form is prepared by conventional methods, formulated as follows:

    ______________________________________                                         Ingredient  Quantity (mg per capsule)                                          ______________________________________                                         Compound 5  200                                                                Lactose     To fill to volume of capsule                                       ______________________________________                                    

The above capsule administered orally once a day substantially reduces the symptomology of a patient afflicted with rheumatoid arthritis or osteoarthritis.

While particular embodiments of the subject invention have been described, it would be obvious to those skilled in the art that various changes and modifications to the compositions disclosed herein can be made without departing from the spirit and scope of the invention. It is intended to cover, in the appended claims, all such modifications that are within the scope of this invention. 

What is claimed is:
 1. A compound having the structure: ##STR6## wherein (a) X is selected from the groups consisting of hydroxy, C₁ to C₂ alkanoxy, thiol, C₁ to C₂ alkanylthiol, and halo;(b) R and R' are each independently selected from the group consisting of C₁ to about C₃ straight or branched alkanyl, and C₃ to C₄ cyclic alkanyl; or R and R' are bonded together to form a C₃ to C₆ cyclic alkanyl ring, or a C₃ to C₅ cyclic heteroalkanyl ring having one oxygen or sulfur atom in the ring, the heteroatom not being bonded to the carbon to which X is bonded; and R and R', or the ring formed by them when bonded together, are each, independently, unsubstituted or monosubstituted with a substituent selected from the group consisting of halo, hydroxy, thiol, C₁ to about C₂ alkanoxy, and C₁ to C₂ alkanylthiol.
 2. The compound of claim 1 wherein X is selected from the group consisting of hydroxy, thiol and halo.
 3. The compound of claim 1 wherein X is chloro or hydroxy.
 4. The compound of claim 2 wherein R' is unsubstituted or substituted methyl or ethyl.
 5. The compound of claim 4 wherein R' is unsubstituted methyl, and R is unsubstituted or substituted alkanyl selected from the group consisting of methyl, ethyl, n-propyl, i-propyl, and cyclopropyl, any substituent of R being selected from the group consisting of fluoro, chloro and methoxy.
 6. The compound of claim 5 wherein X is hydroxy.
 7. The compound of claim 6 wherein R is unsubstituted cyclopropyl.
 8. The compound of claim 5 wherein X is chloro or fluoro.
 9. The compound of claim 8 wherein X is chloro, and R is unsubstituted methyl.
 10. The compound of claim 1 wherein R and R' are bonded together to form an unsubstituted C₃ to C₅ cyclic alkanyl ring.
 11. The compound of claim 10 wherein X is hydroxy.
 12. The compound of claim 10 wherein X is chloro or fluoro.
 13. The compound of claim 1 wherein X is thiol.
 14. The compound of claim 5 wherein X is thiol.
 15. A pharmaceutical composition comprising:(a) a safe and effective amount of the compound of any claims 1, 5, or 10; and (b) a pharmaceutically-acceptable carrier.
 16. A method of treating inflammation or pain comprising the peroral administration of a safe and effective amount of the compound of any of claims 1, 5, or
 10. 